Operation of printing nozzles in additive manufacture and apparatus for cleaning printing nozzles

Abstract

A method of providing nozzle calibration parameters for a 3D printer comprises: printing an arc pattern, printing an X-Y align pattern, and printing a head calibration pattern, measuring actual positions of drops, calculating deviations of said measured actual positions from expected positions, and calculating calibration parameters to correct for the deviations. Indicator drops may be used to allow built-in image recognition to find the calibration drops, and a cam system is provided to guide nozzle wipers.

Description

RELATED APPLICATIONS[0001]This application is a National Phase of PCT Patent Application No. PCT / IL2016 / 050751 having International filing date of Jul. 13, 2016, which claims the benefit of priority under 35 USC § 119(e) of U.S. Provisional Patent Application No. 62 / 191,703 filed on Jul. 13, 2015. The contents of the above applications are all incorporated by reference as if fully set forth herein in their entirety.FIELD AND BACKGROUND OF THE INVENTION[0002]The present invention, in some embodiments thereof, relates to operation of printing nozzles in additive manufacture and, more particularly, but not exclusively, to the accurate and failure free operation of the nozzles.[0003]Nozzles are an important part of a 3D printer and serve the purpose of producing jets of ink droplets which land at specified locations to form the product. In order for the ink to land at the specified location the nozzle must first of all be kept clean of debris which can disrupt the jet and cause it to mi...

AI Technical Summary

Benefits of technology

The patent describes a device that uses a special cam to control the wiper that cleans the nozzles. This allows for precise wiping around the nozzles without damaging the wipers. The device also calibrates the nozzles by printing special droplets that help with image processing. This allows for accurate identification of the droplets.

Problems solved by technology

The position of a single drop fired by a nozzle however cannot be reliably detected since a single drop is very small and indistinct, which makes it difficult to obtain calibration parameters that can be directly used with the model of FIG. 4.

It is thus not possible to determine the vectors describing positions of the printing heads with respect the center of the tray, as shown in FIG. 4.

However, the nozzle plate edges are very sharp and can tear the softer rubber material as it engages the nozzle plate.

Damage to the wiper blade from sliding across the sharp edges of the nozzle plate prevents effective cleaning of the nozzle plate.

During the wiping motion, the wiper blade also wipes along the printhead latches, causing resin to be deposited onto the latches which may build up over time and affect printing.

However the solution requires more parts including an extra motor and thus introduces complexity and cost.

However the solution does not allow a full wipe of the nozzle plate, so that resin buildup may occur.

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